The present invention relates generally to orthopedic braces, and more particularly to an orthopedic knee brace.
Orthopedic braces embody a broad range of apparatuses, each having the common purpose of supporting and/or stabilizing a skeletal joint when worn on the body of a user. The orthopedic brace may serve either a preventative role or a remedial role. In a preventative role, the brace provides added support and stability to a healthy skeletal joint, thereby reducing the risk of injury when the joint is subjected to undue stress. In a remedial role, the brace supports and stabilizes a skeletal joint which has been weakened by injury or other infirmity, thereby reinforcing the joint and reducing the risk of further injury while the joint is rehabilitated.
Conventional orthopedic knee braces may be generally characterized as either frame braces or soft braces. As the name implies, a conventional frame brace has a frame which is secured to the leg by a plurality of straps engaging the frame and circumscribing the leg. The frame typically includes two rotationally-jointed longitudinal supports positioned on opposing sides of the leg. As such, one longitudinal support engages the medial side of the leg at the affected knee to be stabilized as well as the upper and lower leg above and below the affected knee, respectively. The other longitudinal support correspondingly engages the lateral side of the leg.
Each longitudinal support consists of a pair of relatively rigid upper and lower arms and a hinge which rotationally interconnects the upper and lower arms to one another. The upper and lower arms are positioned adjacent to the upper and lower leg, respectively, while the hinge is positioned adjacent to the knee. The frame may also include arcuate-shaped upper and lower cuffs. The upper cuff may be attached to the medial and lateral upper arms and extend therebetween engaging the anterior or posterior face of the upper leg, while the lower cuff may correspondingly be attached to the medial and lateral lower arms and likewise extend therebetween engaging the anterior or posterior face of the lower leg. In a common alternate configuration of the frame, one longitudinal support is omitted from the frame so that only one side of the leg, either the medial or lateral side, is engaged by a longitudinal support. In any case, the frame brace diverts a substantial fraction of the dynamic and static force loads from the knee to the rigid frame, thereby supporting and stabilizing the knee.
A conventional soft brace differs from a frame brace insofar as the soft brace has a compression sleeve which is formed from a pliant material, which wraps around the leg at the knee forming a tube-like structure. The sleeve encloses the knee and a portion of the upper and lower legs adjacent to the knee. The relatively tightly-wrapped sleeve of the soft brace applies radial compression to the knee, thereby supporting and stabilizing the knee. The soft brace may also have one or more straps which engage the sleeve and circumscribe the leg to increase the radially-directed compressive force on the knee. The support and stabilizing function of the soft brace may be further enhanced by incorporating rigid or semi-rigid stays into the sleeve.
One destabilizing condition of the knee joint which can be mitigated by use of a knee brace is osteoarthritis. Knee osteoarthritis is a degenerative disease that results in chronic pain to the subject when the knee is statically or dynamically loaded. Osteoarthritis is commonly the result of aging, joint overuse, or injury. Uni-compartmental osteoarthritic knee pain is caused by an unbalanced loading on the medial or lateral compartment of the knee which closes the clearance space forming the compartment between the condyles of the femur and tibia. When there is contact of the condyles in the afflicted compartment of the knee, abrasion occurs at the contact surface producing pain in the joint.
A number of frame-type knee braces are specifically designed to noninvasively treat osteoarthritis by applying a corrective force to the knee of the user, such as the knee braces disclosed in U.S. Pat. Nos. 5,277,698; 5,458,565 and 5,807,294. If a user's osteoarthritis is caused by overloading the medial compartment of the knee, the frame of these exemplary knee braces is provided with a lateral longitudinal support which exerts a linear biasing force on the knee in the medial direction to reduce the load on the medial compartment. Conversely, if a user's osteoarthritis is caused by overloading the lateral compartment of the knee, the frame is provided with a medial longitudinal support which exerts a linear biasing force on the knee in the lateral direction to reduce the load on the lateral compartment.
The present invention recognizes the need for a soft-type knee brace which has an effective osteoarthritic treatment function. Accordingly, it is generally an object of the present invention to provide a soft brace which satisfies the above-recited need. This object and others are accomplished in accordance with the invention described hereafter.